Distributed multistatic active sonar networks have the potential to increase anti-submarine warfare (ASW) performance against small, quiet, threat submarines in the harsh clutter-saturated littoral and the deeper open-ocean environments. This improved performance comes through the expanded geometric diversity achieved with multiple sources and receivers, and results in increased probability of detection, area coverage, object tracking, classification, and localization through cross-fixing.
However, the increased number of sensors in a multistatic network results in corresponding increases in the data rate, processing, communications requirements, and operator loading. Without an effective fusion of the multistatic data, the benefits of such systems will be unrealizable. Thus, effective, robust, and automated multi-sensor data fusion and tracking algorithms become an essential part of such systems. While much progress has recently been made in the prior art, however, unacceptably high false alarm rates for the data fusion algorithms are still a major issue for such systems. Multistatic fusion algorithms are still challenged to automatically output a sufficiently low false track/alert rate to the operator in reverberation- and clutter-rich conditions, while at the same time providing quality track information for sonar contacts that are detected. Additionally, communication links may not have the throughput capacity to transfer all of the associated data from each of the multistatic nodes to a fusion center.
In view of the above, there is a need for a multistatic active sonar system and method that minimizes false alarm rates by taking advantage of specular echo phenomena of flat or cylindrical objects. There is a further need for a multistatic active sonar system and method that minimizes communication and operator loading by selective transmission of sonar data for track fusion. There is still further need of a multistatic active sonar system and method that uses a dual threshold signal-to-noise ratio scheme to filter out unwanted reverberation and clutter without any significant loss in track quality.